samedi 14 janvier 2017

A Japanese sounding rocket lifted off carrying the TRICOM-1 CubeSat in an experimental launch to see if a sounding rocket, usually used for sub-orbital missions, could orbit a payload.

Liftoff took place at 23:33 UTC from Uchinoura in Japan. Reports came in after launch that the second stage did not ignite after the first stage resulting in a launch failure.

Launch of Japan’s NanoSat Launcher with TRICOM-1 on SS-520 Rocket

The 9.5-meter SS-520-4 rocket, only one-fifth the length of an H-IIA rocket, is based on the two-stage solid-fueled SS-520 model designed to lift observatory equipment to an altitude of about 1,000 km.

With one stage added, the SS-520-4 became one of the smallest rockets in the world capable of putting a satellite into Earth’s orbit. The tiny satellite to be carried by the small rocket is the University of Tokyo’s TRICOM-1, which weighs some 3 kg.

TRICOM 1 spacecraft

Costs to remodel the SS-520 rocket and develop the satellite to take pictures of Earth and conduct communications experiments were cut by using commercial electronic parts.

The project chiefly used ¥400 million provided by the Ministry of Economy, Trade and Industry.

Unveiling the SS-520-4 rocket to the media Monday, Hiroto Habu, an associate professor at JAXA, said, “I really want to make the difficult project successful, because it should help expand the use of the space.”

SpaceX has succeeded in launch a Falcon 9 rocket from Vandenberg Air Force Base in California, its first launch since a Falcon 9 rocket exploded on a launch pad in pre-flight procedures in September 2016. The launch took place at 9:54 AM PT Saturday, during an instant launch window. It’s a huge victory for SpaceX, which has had to delay its launch schedule since the explosion.

The launch also resulted in a successful recovery of the Falcon 9 rocket’s first stage, which marks the seventh time SpaceX has succeed in landing this stage back for potential later re-use. SpaceX’s second-stage also successfully reached low-earth orbit, where it will begin the next stage of the mission, deploying Iridium’s 10 satellites.

SpaceX Falcon 9 Iridium-1 Launch

SpaceX successfully began deploying the Iridium NEXT satellites as of around 11 AM PT/2 PM ET. All satellites were successfully deployed as of 11:13 AM PT / 2:12 PM PT, signalling a successful mission for the space company’s first flight back.

SpaceX Falcon 9 Rocket return

In 2016, SpaceX completed only 8 of a planned 20 launches, due to the September 1 explosion that halted all new launches for four months. That has not been good for the company’s bottom line, resulting in a year that likely saw it exacerbate a reported $250 million loss in 2015.

Iridium NEXT satellite

SpaceX also had to push back its timelines for test launches of its Dragon crew capsule as a result of the September incident. The original target date for a Dragon test launch with people on board was 2017, but it’s now been pushed back to 2018. The company still hopes to fly a mission without crew on board by the last quarter of this year, however.

Crewed mission capabilities will help SpaceX expand its ability to serve contracts, since it can then serve the ISS for more than just supply runs. It also sets the stage for SpaceX’s future goals of providing missions to Mars, with a target initial date for those aspirations still set for 2024.

vendredi 13 janvier 2017

A beam circulated for the first time late on Wednesday evening (12 January 2017) in the pioneering SESAME synchrotron. This is an important milestone on the way to research at the first light-source laboratory in the Middle East.

SESAME, which stands for Synchrotron-light for Experimental Science and Applications in the Middle East, is a particle accelerator-based facility that uses electromagnetic radiation emitted by circulating electron beams to study a range of properties of matter. Experiments at SESAME will enable research in fields ranging from medicine and biology, through materials science, physics and chemistry to healthcare, the environment, agriculture and archaeology.

CERN has a long-standing involvement with SESAME, notably through the European Commission funded CESSAMag project, coordinated by CERN, which provided the magnet system for the SESAME main ring. CESSAMag brought CERN expertise in particle accelerator technology to the service of SESAME, allowing SESAME to concentrate on other key main ring systems. CESSAMag has also provided important training, knowledge and technology transfer.

Image above: The new beam in the pioneering SESAME synchrotron is an important milestone to research at the first Middle East light-source (Image: Noemi Caraban/CERN).

This milestone follows a series of key events, including the establishment of a Middle East Scientific Collaboration group in the mid-1990s. This was followed by the donation of the BESSY1 accelerator by the BESSY laboratory in Berlin. A refurbished and upgraded BESSY1 now serves as the injector for the new SESAME main ring, which is a competitive third-generation light source built by SESAME with support from the SESAME Members, as well as the European Commission and CERN through CESSAMag, and Italy.

The first circulating beam is an important step on the way to first light, which marks the start of the research programme at any new synchrotron light-source facility, but there is much to be done before experiments can get underway. Beams have to be accelerated to SESAME’s operating energy of 2.5 GeV. Then the light emitted as the beams circulate has to be channelled along SESAME’s two day-one beam lines and optimised for the experiments that will take place there. This process is likely to take around six months, leading to first experiments in the summer of 2017.

SESAME was established under the auspices of UNESCO before becoming a fully independent intergovernmental organisation in its own right in 2004. SESAME’s Members are Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, the Palestinian Authority and Turkey. Its mission is to provide a world-class research facility for the region, while fostering international scientific cooperation. Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

The beautiful spiral galaxy visible in the center of the image is known as RX J1140.1+0307, a galaxy in the Virgo constellation imaged by the NASA/ESA Hubble Space Telescope, and it presents an interesting puzzle. At first glance, this galaxy appears to be a normal spiral galaxy, much like the Milky Way, but first appearances can be deceptive!

The Milky Way galaxy, like most large galaxies, has a supermassive black hole at its center, but some galaxies are centered on lighter, intermediate-mass black holes. RX J1140.1+0307 is such a galaxy — in fact, it is centered on one of the lowest black hole masses known in any luminous galactic core. What puzzles scientists about this particular galaxy is that the calculations don’t add up. With such a relatively low mass for the central black hole, models for the emission from the object cannot explain the observed spectrum. There must be other mechanisms at play in the interactions between the inner and outer parts of the accretion disk surrounding the black hole.

(Highlights: Week of Jan. 2, 2017) - While preparation for a spacewalk was a primary focus of crew members, science continued aboard the International Space Station, including flames, miniature satellites and fine motor skills tests.

NASA astronaut Peggy Whitson tested components of an investigation that could lead to more efficient jet and rocket engines. The Elucidation of Flame Spread and Group Combustion Excitation Mechanism of Randomly distributed Droplet Clouds (Group Combustion) tests a theory that fuel sprays change from partial to group combustion as flames spread across clouds of droplets. On the space station, the position of flames and positions of liquid fuel droplets are measured along with temperature distribution as the flame spreads along a test lattice. Microgravity eliminates convection, which allows scientists to gather data points before the droplets and combustion products disperse.

Image above: NASA astronaut Shane Kimbrough captured this image of the Alpha Magnetic Spectrometer (AMS), which is studying cosmic ray particles and has collected data from more than 90 billion cosmic ray events in the five years since it was installed. Image Credit: NASA.

Rocket engines use spray combustion of liquid propellants, but the high speeds of the fuel and oxidizer as they move through the combustion chamber makes it virtually impossible to analyze the flames. JAXA’s (Japan Aerospace Exploration Agency) Group Combustion investigation will help improve simulations used to predict the combustion behavior to assist in the development of advanced rocket engines. This information could also help develop cleaner, more energy-efficient engines for vehicles on Earth.

ESA (European Space Agency) astronaut Thomas Pesquet and Russian cosmonaut Andrei Borisenko performed 11 test runs of the SPHERES Zero Robotics mini-satellites in advance of a competition scheduled for later in January. Student teams are challenged to design research for the station by writing programs for tasks the SPHERES satellites can accomplish that would be relevant to future space missions. The bowling-ball-sized satellites can be programmed to move about the space station cabin. SPHERES stands for Synchronized Position Hold, Engage, Reorient, Experimental Satellites. A major outreach tool as well as scientific investigation, SPHERES Zero Robotics provides a unique and valuable opportunity for students interested in science, technology, engineering and mathematics -- STEM -- careers.

Image above: A sampling of the many cameras stowed on the International Space Station exhibits how much photography is a part of daily life in orbit, whether to capture important images of science experiments or stunning vistas of Earth below. Image Credit: NASA.

Pesquet and Whitson completed flight day 50 sessions for the Effects of Long-Duration Microgravity on Fine Motor Skills (Fine Motor Skills) investigation. Fine motor skills are crucial for successfully interacting with touch-based technologies, repairing sensitive equipment and a variety of other tasks. For NASA's Fine Motor Skills investigation, crew members perform a series of interactive tasks on a touchscreen tablet. The investigation is the first fine motor skills study to measure long-term microgravity exposure, different phases of microgravity adaptation, and sensorimotor recovery after returning to Earth gravity. The simple tasks developed for this investigation may have wide-reaching benefits for elderly patients, people with motor disorders or patients with brain injuries on Earth undergoing rehabilitation for conditions that impair fine motor control.

Image above: This image of the Glorioso Islands, located just off the northwest coast of Madagascar, was captured by an Expedition 50 crew member aboard the space station. Image Credit: NASA.

Crew members conducted other human research investigations this week, including Body Measures, Habitability, Fluid Shifts, Dose Tracker and Space Headaches.

Widespread flooding has recently caused the deaths of dozens of people in southern Thailand. Frequent and persistent downpours have resulted in record rainfall totals and NASA calculated rainfall over the region from January 5 to January 12, 2017.

Image above: NASA calculated rainfall over southern Thailand from Jan. 5 to 12, 2017. Extreme rainfall totals of over 700 mm (27.6 inches) were found over the Gulf of Thailand. Highest totals over land were greater than 500 mm (19.7 inches) on the eastern coast of the Malay Peninsula in the Bang Saphan District. Image Credits: NASA/JAXA, Hal Pierce.

The Global Precipitation Measurement mission or GPM core satellite is part of a constellation of satellites that can measure rainfall from space. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency and the data is input into NASA's Integrated Multi-satellitE Retrievals for GPM (IMERG) data product.

IMERG was used to estimate the total amount of rain that fell over southern Thailand over the week. Extreme rainfall totals of over 700 mm (27.6 inches) were found over the Gulf of Thailand. The highest rainfall total estimates over land were greater than 500 mm (19.7 inches) on the eastern coast of the Malay Peninsula in the Bang Saphan District.

Rainfall has greatly increased over Thailand during this La Nina year. Very low rainfall totals occurred over Thailand during last year's El Nino event. At NASA's Goddard Space Flight Center in Greenbelt, Maryland, a rainfall anomaly analysis was made by comparing the former Tropical Rainfall Measuring Mission or TRMM calibrated rainfall climatology to "near real-time" Multi-satellite Precipitation Analysis data collected over a thirty day period.

About NASA's TMPA Analysis

The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) has been used to monitor rainfall over the global Tropics for many years. By subtracting the long-term average rainfall or climatology, rainfall anomalies can be constructed to show deviations from the normal pattern.

TRMM is the Tropical Rainfall Measuring Mission satellite that was in operation from 1997 to April 2015. It was designed to measure rainfall over the global Tropics using both passive and active sensors, including the first and at the time only precipitation radar in space. With its combination of passive microwave and active radar sensors, TRMM was used to calibrate rainfall estimates from other satellites to expand its coverage. The TRMM satellite produced over 17 years of precipitation measurements that were a valuable contribution to global rainfall climatology.

TRMM's successor, the Global Precipitation Measurement mission or GPM core satellite was launched on February 27, 2014. TRMM and GPM are joint missions between NASA and the Japanese space agency JAXA.

Thai Meteorological Department Issues Heavy Rain Warning

Image above: In this rainfall analysis, the panel on the left shows rainfall departure from normal during the 2016 El Nino event. The panel (right) shows the extreme increase in rainfall over southern Thailand during the current La Nina event. Image Credits: NASA/JAXA, Hal Pierce.

On January 13, 2017 the Thai Meteorological Department (TMD) issued a Weather Warning for Heavy Rains in Lower South and Strong Wind in Gulf [of Thailand]. The Gulf borders southwestern Thailand, Cambodia, and southern Vietnam. It is up to 350 miles (563 km) wide and 450 miles (724 km) long.

The TMD warning stated "By 15 January, the moderate high pressure from China will extend to upper Thailand inducing the stronger northeast monsoon prevailing across the Gulf and the South. Outbreaks of more rain will be expected. During 16-18 January, isolated heavy rain will be forecast especially for provinces: Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, and Narathiwat. People should beware of severe conditions and possible flash flood. Areas prone to landslide are still watched and people follow closely the weather update. The strong winds over the Gulf force waves up to 2-3 meters. People along the Gulf shore should beware of inshore surf. All ships proceed with caution and small boats keep."

NASA Analyzes Heavy Rainfall Over Southern Thailand

Video above: NASA calculated rainfall over southern Thailand from Jan. 5 to 12, 2017. Extreme rainfall totals of over 700 mm (27.6 inches) were found over the Gulf of Thailand. Highest totals over land were greater than 500 mm (19.7 inches) on the eastern coast of the Malay Peninsula in the Bang Saphan District. Video Credits: NASA/JAXA, Hal Pierce.

This week, ESA deep-space radio dishes on two continents are listening for signals from the international Cassini spacecraft, now on its final tour of Saturn.

ESA’s sensitive tracking antennas at New Norcia, Western Australia, and Malargüe, Argentina, are being called in to help with crucial observations during Cassini’s last months in orbit, dubbed the ‘Grand Finale’.

The Cassini–Huygens mission is one of the most successful exploration endeavours ever.

Above Saturn

Launched in October 1997, the Cassini orbiter delivered Europe’s Huygens probe to the surface of Saturn’s mysterious moon Titan in 2005, just a few months after becoming the first spacecraft to enter orbit around the giant gas planet.

In addition to Huygens’ historic delivery 12 years ago on 14 January, Cassini has returned a wealth of information from Saturn’s system, including images and other data from the massive planet, its multiple moons and its hauntingly beautiful system of rings.

Now running low on fuel, Cassini will be commanded to dive into Saturn’s upper atmosphere on 15 September, where it will burn up like a meteor.

Huygens landing on Titan

As part of its final ambitious observing plan, the craft began last month making a series of 20 orbits, arcing high above the planet’s north pole then diving down, skimming the narrow F-ring at the edge of the main rings.

Then, starting in April, Cassini will leap over the rings to begin its final series of 22 daring dives, taking it between the planet and the inner edge of the rings.

ESA's Big Iron listens in

Between December 2016 and July 2017, ESA' ground stations will work with NASA’s Deep Space Network to record radio signals transmitted by Cassini across 1.6 billion km, helping scientists to study Saturn’s atmosphere and its enigmatic rings, bringing us closer to understanding its origins.

New Norcia tracking station

They will record signals transmitted from Cassini that have crossed or bounced off Saturn’s atmosphere or rings. Variations in the strength and frequency contain valuable information on the composition, state and structure of whatever they have passed through.

In addition, tiny wobbles in Cassini’s orbit due to the varying pull of gravity can be teased from the signals, helping to build our understanding of the planet’s interior.

First passes

The first three recording passes involving ESA stations were conducted in December, followed by two more on 3 and 10 January. Twenty more deep-space link-ups are scheduled.

“For the first few months of 2017, we’re mostly recording signals that will transit through the ring system or the atmosphere,” says Daniel Firre, the service manager at ESA’s mission control centre in Darmstadt, Germany.

“After April, as Cassini’s orbit gets lower, we’ll switch to recording signals to be used for gravity analysis.”

Cassini Ring Dive Ride Along

The recordings – some batches comprising up to 25 GB – are passed to the Cassini radio science team for analysis.

“The ESA stations are helping to acquire extremely important radio science data from Cassini, highlighting how interagency cooperation can make planetary missions even more valuable,” notes Aseel Anabtawi, from the radio science group at NASA’s Jet Propulsion Laboratory.

Some recording contacts between Cassini and Earth will last over 10 hours, and require technically complex handovers of the signal from an ESA to a NASA station and vice versa. In addition, specialists in Darmstadt must perform very precise frequency calculations for the recording passes.

“Supporting Cassini radio science for the mission’s Grand Finale requires not only teamwork at ESA, but also deep collaboration between the agencies,” says ESA’s Thomas Beck, responsible for ground station services.

“This is part of our continuing mutual support that is yielding real scientific and engineering value.”

This image of a crescent Jupiter and the iconic Great Red Spot was created by a citizen scientist (Roman Tkachenko) using data from Juno's JunoCam instrument. You can also see a series of storms shaped like white ovals, known informally as the ‘string of pearls.’ Below the Great Red Spot a reddish long-lived storm known as Oval BA is visible.

The image was taken on Dec. 11, 2016 at 2:30 p.m. PST (5:30 p.m. EST), as the Juno spacecraft performed its third close flyby of Jupiter. At the time the image was taken, the spacecraft was about 285,100 miles (458,800 kilometers) from the planet.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. Caltech in Pasadena, California, manages JPL for NASA.

Expedition 50 Commander Shane Kimbrough and Flight Engineer Thomas Pesquet concluded their spacewalk at 12:20 p.m. EST. During the nearly six hour spacewalk, the two NASA astronauts successfully installed three new adapter plates and hooked up electrical connections for three of the six new lithium-ion batteries on the International Space Station.

The new lithium-ion batteries and adapter plates replace the nickel-hydrogen batteries currently used on the station to store electrical energy generated by the station’s solar arrays. These new batteries provide an improved power capacity for operations with a lighter mass and a smaller volume than the nickel-hydrogen batteries. Robotic work to update the batteries began in January. This was the second of two spacewalks to finalize the installation. Additional batteries will be replaced as part of this power upgrade over the next couple of years as new batteries are delivered to station.

Astronauts were also able to accomplish several get-ahead tasks including stowing padded shields from Node 3 outside of the station to make room inside the airlock and taking photos to document hardware for future spacewalks.

This was the second spacewalk in a week for Kimbrough and the fourth of his career, and the first for Pesquet in the refurbishment of two of the station’s eight power channels.

Space Station Spacewalkers Continue Power Upgrades on Orbital Outpost

Space station crew members have conducted 197 spacewalks in support of assembly and maintenance of the orbiting laboratory. Spacewalkers have now spent a total of 51 days 6 hours and 4 minutes working outside the station.

jeudi 12 janvier 2017

This image of a well-preserved unnamed elliptical crater in Terra Sabaea, is illustrative of the complexity of ejecta deposits forming as a by-product of the impact process that shapes much of the surface of Mars.

Here we see a portion of the western ejecta deposits emanating from a 10-kilometer impact crater that occurs within the wall of a larger, 60-kilometer-wide crater. In the central part is a lobe-shaped portion of the ejecta blanket from the smaller crater. The crater is elliptical not because of an angled (oblique) impact, but because it occurred on the steep slopes of the wall of a larger crater. This caused it to be truncated along the slope and elongated perpendicular to the slope. As a result, any impact melt from the smaller crater would have preferentially deposited down slope and towards the floor of the larger crater (towards the west).

Within this deposit, we can see fine-scale morphological features in the form of a dense network of small ridges and pits. These crater-related pitted materials are consistent with volatile-rich impact melt-bearing deposits seen in some of the best-preserved craters on Mars (e.g., Zumba, Zunil, etc.). These deposits formed immediately after the impact event, and their discernible presence relate to the preservation state of the crater. This image is an attempt to visualize the complex formation and emplacement history of these enigmatic deposits formed by this elliptical crater and to understand its degradation history.

Expedition 50 astronauts Shane Kimbrough and Thomas Pesquet are ready for their mission’s second spacewalk that starts Friday at 7 a.m. EST. The duo will wrap up power maintenance work to connect new lithium-ion batteries and install adapter plates. Kimbrough and NASA astronaut Peggy Whitson started that work last Friday during a six-hour, 32-minute spacewalk. Live broadcasting at: https://www.nasa.gov/multimedia/nasatv/index.html

Both spacewalks complement the ongoing robotics work that started at the end of December. Ground controllers have been remotely-operating the Canadarm2 robotic arm and Dextre robotic hand to remove and stow the old nickel-hydrogen batteries and the install the new batteries.

The three cosmonauts have been staying focused on their set of Russian space research and lab maintenance. Station veterans Andrey Borisenko and Oleg Novitskiy collected blood samples for a pair human research studies looking at bone loss and stress responses caused by living in space. First-time station resident Sergy Ryzhikov explored chemical reactions caused by jet engine exhaust in the Earth’s upper atmosphere.

After a two-and-a-half-hour descent, the metallic, saucer-shaped spacecraft came to rest with a thud on a dark floodplain covered in cobbles of water ice, in temperatures hundreds of degrees below freezing. The alien probe worked frantically to collect and transmit images and data about its environs -- in mere minutes its mothership would drop below the local horizon, cutting off its link to the home world and silencing its voice forever.

Titan Touchdown

Although it may seem the stuff of science fiction, this scene played out 12 years ago on the surface of Saturn's largest moon, Titan. The "aliens" who built the probe were us. This was the triumphant landing of ESA's Huygens probe.

Huygens, a project of the European Space Agency, traveled to Titan as the companion to NASA's Cassini spacecraft, and then separated from its mothership on Dec. 24, 2004, for a 20-day coast toward its destiny at Titan.

The probe sampled Titan's dense, hazy atmosphere as it slowly rotated beneath its parachutes, analyzing the complex organic chemistry and measuring winds. It also took hundreds of images during the descent, revealing bright, rugged highlands that were crosscut by dark drainage channels and steep ravines. The area where the probe touched down was a dark, granular surface, which resembled a dry lakebed.

Thoughts on Huygens

Today the Huygens probe sits silently on the frigid surface of Titan, its mission concluded mere hours after touchdown, while the Cassini spacecraft continues the exploration of Titan from above as part of its mission to learn more about Saturn and its moons. Now in its dramatic final year, the spacecraft's own journey will conclude on September 15 with a fateful plunge into Saturn's atmosphere.

Image above: Images taken by Huygens were used to create this view, which shows the probe's perspective from an altitude of about 6 miles (10 kilometers). Image credits: ESA/NASA/JPL/University of Arizona.

With the mission heading into its home stretch, Cassini team members and NASA leaders look back fondly on the significance of Huygens:

"The Huygens descent and landing represented a major breakthrough in our exploration of Titan as well as the first soft landing on an outer-planet moon. It completely changed our understanding of this haze-covered ocean world." -- Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, California

"The Huygens images were everything our images from orbit were not. Instead of hazy, sinuous features that we could only guess were streams and drainage channels, here was incontrovertible evidence that at some point in Titan's history -- and perhaps even now -- there were flowing liquid hydrocarbons on the surface. Huygens' images became a Rosetta stone for helping us interpret our subsequent findings on Titan." -- Carolyn Porco, Cassini imaging team lead at Space Science Institute, Boulder, Colorado

"Cassini and Huygens have shown us that Titan is an amazing world with a landscape that mimics Earth in many ways. During its descent, the Huygens probe captured views that demonstrated an entirely new dimension to that comparison and highlights that there is so much more we have yet to discover. For me, Huygens has emphasized why it is so important that we continue to explore Titan." -- Alex Hayes, a Cassini scientist at Cornell University, Ithaca, New York

"Twelve years ago, a small probe touched down on an orangish, alien world in the outer solar system, marking humankind's most distant landing to date. Studying Titan helps us tease out the potential of habitability of this tiny world and better understand the chemistry of the early Earth." -- Jim Green, director of planetary science at NASA Headquarters, Washington

A collection of Huygens' top science findings is available from ESA at:

mercredi 11 janvier 2017

Commander Shane Kimbrough is getting ready for his second spacewalk in a week to complete the upgrade of power systems on the International Space Station. He will be joined by Thomas Pesquet from the European Space Agency who will be conducting his first spacewalk.

ESA astronaut Thomas Pesquet is set for his first spacewalk, on Friday 13 January. Together with NASA astronaut Shane Kimbrough, he will exit the International Space Station at 12:05 GMT (13:05 CET) to complete a battery upgrade to the outpost’s power system. Live broadcasting at: https://www.nasa.gov/multimedia/nasatv/index.html

The spacewalking duo are partnering up today with NASA astronaut Peggy Whitson to review Friday morning’s spacewalk. Whitson, who completed her seventh spacewalk last Friday, and cosmonaut Oleg Novitskiy will be assisting the spacewalkers in and out of their spacesuits and the Quest airlock.

Image above: Astronaut Shane Kimbrough is pictured during the first power upgrade spacewalk on Jan. 6, 2017. Image Credit: NASA.

Late yesterday and last night robotic ground controllers used the Dextre Special Purpose Dexterous Manipulator to move the final lithium-ion battery to the 1A power channel Integrated Electronics Assembly, moved another nickel-hydrogen battery to one of Dextre’s arms for temporary stowage and tightened down bolts on two of the previously moved Li-ion batteries.

So, we now have five nickel-hydrogen batteries either on the HTV External Pallet or temporarily stowed on Dextre and one more Ni-H battery to move from the 1A IEA to another stowage position on Dextre later today to complete the pre-EVA robotics. All six new lithium-ion batteries are now installed on the S4 truss IEA. The 3A power channel is fully operational. The 1A power channel will be activated on Friday during the EVA after adapter plates are moved into place on the 1A IEA.

Post-EVA robotics on Saturday and Sunday will complete the work to move the last four old Ni-H batteries from Dextre to the External Pallet for disposal (there will be nine on the EP in all). They will burn up in the Earth’s atmosphere when the HTV is deorbited.

Animated Earth views seen from ISS. Animation Credit: NASA

Whitson and Pesquet started their day scanning their arteries with and ultrasound and collecting body fluid samples for the Cardio Ox study. That experiment is researching the increased risk of atherosclerosis, the plaque build-up in the artery wall that results in narrowing of the blood vessel, in astronauts living in space.

In the Russian segment of the space station, cosmonaut Sergey Ryzhikov set up gear for a Matryoshka radiation detection experiment. Veteran cosmonaut Andrey Borisenko studied how mission events affect the station structure and explored new Earth photography techniques.

For centuries drought has come and gone across northern sub-Saharan Africa. In recent years, water shortages have been most severe in the Sahel—a band of semi-arid land situated just south of the Sahara Desert and stretching coast-to-coast across the continent, from Senegal and Mauritania in the west to Sudan and Eritrea in the east. Drought struck the Sahel most recently in 2012, triggering food shortages for millions of people due to crop failure and soaring food prices.

Various factors influence these African droughts, both natural and human-caused. A periodic temperature shift in the Atlantic Ocean, known as the Atlantic Multi-decadal Oscillation, plays a role, as does overgrazing, which reduces vegetative cover, and therefore the ability of the soil to retain moisture. By replacing vegetative cover’s moist soil, which contributes water vapor to the atmosphere to help generate rainfall, with bare, shiny desert soil that merely reflects sunlight directly back into space, the capacity for rainfall is diminished.

Image above: Numerous fires create a smoky pall over the skies of western Africa. The image above was acquired on December 10, 2015. Image Credits: NASA Earth Observatory image by Joshua Stevens, using VIIRS data from Suomi NPP.

Another human-caused culprit is biomass burning, as herders burn land to stimulate grass growth, and farmers burn the landscape to convert terrain into farming land and to get rid of unwanted biomass after the harvest season. As with overgrazing, fires dry out the soil and stymie the convection that brings rainfall. Small particles called aerosols that are released into the air by smoke may also reduce the likelihood of rainfall. This can happen because water vapor in the atmosphere condenses on certain types and sizes of aerosols called cloud condensation nuclei to form clouds; when enough water vapor accumulates, rain droplets are formed. But have too many aerosols and the water vapor is spread out more diffusely to the point where rain droplets don’t materialize.

The relationship between fire and the water in northern sub-Saharan Africa, however, had never been comprehensively investigated until recently. A study published in the journal Environmental Research Letters, led by Charles Ichoku, a senior scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, seeks to shed light on the connection.

“We wanted to look at the general impacts of burning on the whole spectrum of the water cycle,” said Ichoku.

To do so, Ichoku and his colleagues used satellite records from 2001 to 2014 — including data from NASA’s Moderate Resolution Imaging Spectroradiometer and the Tropical Rainfall Measurement Mission — to analyze the impact of fires on various water cycle indicators, namely soil moisture, precipitation, evapotranspiration and vegetation greenness. Other work performed by the group focused more closely on examining the interactions between clouds and smoke and also the effects of fires on surface brightness.

Image above: The Suomi NPP satellite detected these fires (red dots) in Africa on January 30, 2016. Ichoku hypothesizes that such fires play a significant role in altering rainfall patterns. Image Credits: NASA Earth Observatory map by Joshua Stevens, using VIIRS data from Suomi NPP.

When Ichoku used satellite data to match fire activity to hydrological indicators, a pattern emerged. “There is a tendency for the net influence of fire to suppress precipitation in northern sub-Saharan Africa,” he said.

For example, in years that had more than average burning during the dry season, measurements of soil moisture, evaporation and vegetation greenness—all of which help to trigger rain—decreased in the following wet season. Even within dry seasons, the amount of water decreased in areas with more humid climates as the burning became more severe.

The results so far show only a correlation between fires and water cycle indicators, but the data gathered from the study is allowing scientists to improve climate models to be able to establish a more direct relationship between biomass burning and its impacts on drought.

For example, the research team is now incorporating the rate of radiant heat output from fires as well as the rate of fire-induced land-cover conversion into regional models, including the NASA Unified Weather Research and Forecasting model. Such new capability will enable the simulation of real fire impacts on drought.

Future modeling may explain some of the study’s seemingly paradoxical findings, including the fact that, even as fires decreased by 2 to 7 percent each year from 2006 to 2013, precipitation during those years did not increase proportionately.

Suomi NPP satellite. Image Credit: NASA

Ichoku thinks one possible reason a decrease in fires didn’t result in more precipitation has to do with the change in the types of lands that are being burned. The study found that throughout the same period, more forests and wetlands were being converted to cropland than in previous years. He notes that recent droughts have drawn people to farm areas that have more water. The drawback is that such land types provide a significant amount of moisture to the atmosphere that eventually becomes rain, so their conversion to farmland poses a threat to future water availability.

“The removal of vegetal cover through burning would likely increase water runoff when it rains, potentially reducing their water retention capacity and invariably the soil moisture,” Ichoku said. “The resulting farming would likely deplete rather than conserve the residual moisture, and in some cases, may even require irrigation. Therefore, such land cover conversions can potentially exacerbate the drought.”

mardi 10 janvier 2017

(Highlights: Week of Dec. 26, 2016) - The end of the calendar year also brought the end to another successful season of vegetable growth on the International Space Station.

NASA astronaut Shane Kimbrough completed the third and final harvest of red lettuce to close out the Veg-03 investigation. Understanding how plants respond to microgravity is an important step for future long-duration space missions, which will require crew members to grow their own food. Crew members on the station have previously grown lettuce and flowers in the Veggie facility. This new series of the study expands on previous validation tests. After collecting the lettuce, Kimbrough cleaned and powered down the Veggie facility.

Image above: NASA astronaut Shane Kimbrough collected the third and final harvest of this round of the Veggie investigation, testing the capability to grow fresh vegetables on the International Space Station. He is seen here, floating with some of the lettuce leaves aboard the station. Image Credit: NASA.

Veggie provides lighting and necessary nutrients for plants in the form of a low-cost growth chamber and planting pillows, which deliver nutrients to the root system. The Veggie pillow concept is a low-maintenance, modular system that requires no additional energy beyond a special light to help the plants grow. It supports a variety of plant species that can be cultivated for fresh food, and even for education experiments.

Crew members have commented that they enjoy space gardening, and investigators believe growing plants could provide a psychological benefit to crew members on long-duration missions, just as gardening is often an enjoyable hobby for people on Earth. Data from this investigation could benefit agricultural practices on Earth by designing systems that use valuable resources such as water more efficiently.

Image above: ESA astronaut Thomas Pesquet uses a long-lens camera to capture Earth observations from a window in the Russian Zvezda module. The Crew Earth Observation investigation is one of the longest-running investigations aboard the space station. Image Credit: NASA.

A ground team commanded the Additive Manufacturing Facility (Manufacturing Device) on the space station to print two items: a sample build for future materials studies and a design that was part of a student contest. Installed on the station in 2015, the Manufacturing Device is a 3-D printer that uses additive manufacturing to build a part layer by layer using an engineered plastic polymer as raw material.

The Manufacturing Device is another step toward a permanent manufacturing capability on the space station. It will enable the production of components and tools on demand in orbit, which will allow further research into manufacturing for long-term missions. The station crew can use it to print a variety of items to perform maintenance, build tools and repair sections in case of an emergency, leading to a reduction in cost, mass, labor and production time. Further research will also help develop this advanced technology for use on Earth.

NASA astronaut Peggy Whitson retrieved the passive air samplers for the Aerosol Sampling experiment, stowing them for return to Earth. Aerosols are small particles suspended in the air. In Earth’s atmosphere, aerosols include soot, dust, pollen and a wide range of other natural and human-made materials. Smoke does not rise and dust does not settle in microgravity the way they do on Earth, causing aerosols to behave differently and posing hazards for crew members breathing the air. Aerosol Sampler collects airborne particles in the station’s air and returns them to Earth so scientists can study the particles with powerful microscopes. For this experiment, particles collected from cabin air are analyzed using a variety of microscopic techniques. Studying these particulates can allow scientists to improve the design of monitors for long-duration missions and help create better fire detectors that can discriminate between dust or background particles and smoke in order to reduce false alarms.

This delicate smudge in deep space is far more turbulent than it first appears. Known as IRAS 14348-1447 — a name derived in part from that of its discoverer, the Infrared Astronomical Satellite (IRAS for short) — this celestial object is actually a combination of two gas-rich spiral galaxies. This doomed duo approached one another too closely in the past, gravity causing them to affect and tug at each other and slowly, destructively, merge into one. The image was taken by Hubble’s Advanced Camera for Surveys (ACS).

IRAS 14348-1447 is located over a billion light-years away from us. It is one of the most gas-rich examples known of an ultraluminous infrared galaxy, a class of cosmic objects that shine characteristically — and incredibly — brightly in the infrared part of the spectrum. Almost 95% of the energy emitted by IRAS 14348-1447 is in the far-infrared!The huge amount of molecular gas within IRAS 14348-1447 fuels its emission, and undergoes a number of dynamical processes as it interacts and moves around; these very same mechanisms are responsible for IRAS 14348-1447’s own whirling and ethereal appearance, creating prominent tails and wisps extending away from the main body of the galaxy.

Careful sleuthing through decade-old images has enabled ESA’s asteroid team to decide that a newly discovered space rock poses little threat of hitting Earth any time soon.

Spotting a previously unknown asteroid for the first time always raises the big question: is there a risk it will impact Earth?

Looking up

Yet, upon discovery, analysts often have very little to go on. The initial image from the observatory, survey team or individual backyard astronomer who spotted the rock typically gives only basic information – its location in the sky and its brightness – and sometimes these aren’t known terribly accurately.

The most crucial information needed to determine with any degree of confidence whether it is a ‘near-Earth object’ (NEO) – and that it will miss Earth (or not) – is the new object’s path. And determining that requires a series images acquired over a period of days or even months.

“We need multiple follow-on images to compute the trajectory and make a risk estimate, but even then the uncertainty can be very large. It really takes many months of observations to get a good, reliable impact risk estimate, and in the meantime, there can be reason to worry,” says Ettore Perozzi of the NEO Coordination Centre at ESA’s facility in Italy.

Spotted from Arizona

This is precisely what happened on 19 October, when asteroid 2016 WJ1 was discovered by the Catalina Sky Survey.

Asteroid 2016 WJ1

“The additional images allowed us to refine our knowledge of the trajectory sufficiently to begin searching astronomical archives, to see if anyone had previously imaged this asteroid without having recognised it as such,” says Marco Micheli, observer at the NEO centre.

If any were found, the team would score what astronomers call a ‘precovery’ – short for pre-discovery.

Precovering

The investigation quickly bore fruit: images found online from the Pan-STARRS survey taken earlier in October showed what might be the target asteroid.

While these were inconclusive, the team assumed they were, in fact, accurate and then used these to call up additional, highly accurate images from a Canadian astronomical image search system.

Bingo: two sets of images from 4 and 5 July 2003 with the Canada–France–Hawaii Telescope were found.

ESA observatory

“After careful inspection we were able to pinpoint the object, and the team were able to perform some very accurate determinations,” says Detlef Koschny, responsible for the NEO portion of ESA’s Space Situational Awareness programme.

“The result was that we could preclude any risk of Earth impact from asteroid 2016 WJ1 anytime soon or well into the future.”

ESA is now developing a new set of automated, wide-field-of-view ‘Fly-Eye’ telescopes that will conduct nightly sky surveys, creating a large future archive of images that will make critical precovery confirmations more efficient in future.